Background: Atopic dermatitis (AD) is a highly heterogeneous disease clinically and biologically. Serum biomarkers have been utilized for endotype identification and have the potential to be predictors for treatment. Objectives: To explore the serum biomarker-based endotypes of Chinese patients with AD and to identify biomarkers for prediction of the efficacy of dupilumab. Methods: Sera from 125 patients with moderate-to-severe AD and 60 normal controls (NC) were analysed for 24 cytokines/chemokines using the magnetic Luminex assay. After the patients received 16 weeks of dupilumab treatment, the efficacy was evaluated, and blood eosinophils, serum immunoglobulin (Ig) E and biomarkers were measured. Results: Chinese patients with moderate-to-severe AD were characterized by T-helper (Th)2-dominant serum biomarkers that were mixed with differentially increased Th1-, Th17- and Th22-type cytokines/chemokines, and it was mainly Th2-type serum biomarkers that were positively correlated with disease severity and eosinophil counts. Adult (but not adolescent or elderly) patients with AD showed a consistent and more significant increase of biomarkers across different types of inflammation. The patients were grouped into two clusters by unsupervised k-means analysis, which were differentially associated with inflammation. Treatment with dupilumab decreased the levels of most cytokines/chemokines analysed. While there was no difference between the two clusters in the efficacy of dupilumab, baseline levels of CD25/soluble interleukin (sIL)-2Rα, IL-31 and IL-36β were identified as predictive factors associated with the efficacy. Conclusions: Our study revealed two inflammation-related endotypes of Chinese patients with AD based on serum biomarkers. High levels of CD25/sIL-2Rα, IL-31 and IL-36β might predict good efficacy of dupilumab treatment.

Background/Objective: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by diverse clinical manifestations. However, variations in its clinical presentations across different ages, genders, anatomical sites, and seasons remain incompletely understood. The objective was to explore the clinical heterogeneities of AD using data from the Chinese non-selective registration system. Methods: A prospective analysis was conducted on 3829 AD patients enrolled in the Chinese Non-selective Registry for AD (CNRAD) at hospital settings from 2020 to 2022. Demographic profiles; distribution, type, and severity of the skin lesion; laboratory findings; allergic comorbidities; family history; and exacerbating factors were analyzed. Results: The male-to-female ratio was 0.92 among adolescent and adult AD patients but increased to 2.11 in elderly AD patients, highlighting an age-dependent gender difference in AD prevalence. Age groups displayed distinct anatomical preferences for lesion distribution, with reduced involvement of the cubital and popliteal fossae in adult and elderly patients. Based on skin lesion characteristics, ten clinical subtypes of AD were proposed. Elderly AD patients exhibited higher severity, compared to adolescence and adult AD patients, with male patients being more severe than females. Elderly AD patients showed a lower proportion of extrinsic type, compared to childhood AD patients. Seasonal change emerged as the most important factor triggering AD flares. Conclusions: This study provides new insights into the heterogeneities of AD clinical manifestations in the Chinese population, demonstrating their significant dependence on temporal factors, including age and season.

Objective: Elderly atopic dermatitis (AD) is a newly identified subtype of AD. Whether specific diagnostic criteria are needed for elderly AD has been debated. This study aimed to propose diagnostic criteria for elderly AD and evaluate the sensitivity. Methods: A hospital-based study was conducted. We screened the clinical features of 1,312 patients with AD of different ages in 1 cohort and proposed a set of diagnostic criteria for elderly AD. The criteria were then validated in another cohort of 223 patients clinically diagnosed with elderly AD by dermatologists specialized in AD to examine the diagnostic sensitivity compared with other criteria by chi-square test. Results: Based on the patients’ clinical features, a set of diagnostic criteria for elderly AD were proposed. The new diagnostic criteria showed significantly higher sensitivity than the classical diagnostic criteria (P < 0.001), especially for mild and moderate AD (P < 0.001). Of all 223 patients with elderly AD, 93.3% fulfilled our criteria, while only 43.5%, 65.5%, and 52.0% fulfilled the Hanifin and Rajka criteria, the Japanese Dermatology Academy criteria, and the United Kingdom Working Party criteria, respectively. Conclusion: The newly proposed criteria for elderly AD yielded high diagnostic sensitivity, particularly for mild and moderate AD.